Certain types of electronic amplifiers, such as audio amplifiers, spend much of the time with little to no output drive. However, an amplifier that is powered still dissipates power when there is no input signal to be amplified due to idle current (i.e., quiescent current, bias current) in the amplifier. Because amplifiers spend considerable time idling, reducing the idle current in an amplifier can save considerable amounts of power, which can extend play time in battery-powered devices.